Deck 6: Microbial Genetics

Question 1

Which of the following is not a difference in the way gene expression occurs in bacteria and in eukaryotes?

A) In bacteria, but not eukaryotes, RNA polymerase binds the promoter directly.
B) Bacteria, but not eukaryotes, have non-coding regions called introns in their genes, which must be removed from mRNA following transcription.
C) In bacteria, but not eukaryotes, translation can begin on a particular mRNA, before transcription of that same mRNA molecule is complete.
D) The ribosomes used by bacteria in translation are smaller and somewhat different in structure than those used by eukaryotes.
E) Gene expression is generally quicker in bacteria than it is in eukaryotes.

Answer 1

B

Question 2

Which of the following components is not normally found as part of a DNA nucleotide?

A) a nitrogenous base
B) a phosphate group
C) uracil
D) a deoxyribose sugar

Answer 2

C

Question 3

The region of the DNA to which RNA polymerase binds during transcription is known as the ________.

A) promoter
B) codon
C) anticodon
D) operator
E) origin of replication

Answer 3

A

Question 4

Protein synthesis occurs on ________, which are composed of proteins and ________.

A) ribosomes; mRNA
B) operons; mRNA
C) promoters; rRNA
D) ribosomes; rRNA
E) active sites; DNA

Question 5

Explain how RNA differs in structure from DNA.

Question 6

The uptake of naked DNA by some bacterial cells is called ________.

A) transduction
B) conjugation
C) an insertion
D) transformation
E) a point mutation

Question 7

How does "proofreading" by DNA polymerase occur during DNA replication?

Question 8

Identify and describe three distinct ways in which genetic recombination occurs in bacteria.

Question 9

Which of the following statements is true?

A) Individuals of the same species have the same genes, but may have different alleles of those genes.
B) Individuals of the same species have different genes but the same alleles.
C) Individuals of the same species have the same genes and alleles as each other.
D) Individuals of the same species have different genes and alleles from each other.

Question 10

________ use(s) codons to specify which amino acid should be added to the growing polypeptide chain during protein synthesis.

A) DNA
B) mRNA
C) tRNA
D) rRNA
E) operons

Question 11

The term used to describe the orientation of the two strands of DNA is:

A) polarity.
B) complementary.
C) antiparallel.
D) 5^' to 3.^'
E) forked.

Question 12

In the lac-operon, under which of the following conditions will the repressor protein be bound to its binding site?

A) when the environment contains abundant lactose
B) when the environment is very low in lactose
C) when the inducer is bound to the repressor
D) when RNA polymerase is most able to bind to the promoter
E) when the structural genes of the operon are being transcribed at a maximum rate

Question 13

Which of the following mutations is most likely to prove beneficial to the cell experiencing the mutation?

A) samesense mutation
B) missense mutation
C) nonsense mutation
D) frameshift mutation
E) spontaneous mutation